Page 23 - Commercial Vehicle Engineer - December 2019

Cost concerns
It is often claimed that maintenance
costs of battery-electric commercial vehicles are substantially lower than
those of comparable diesel vehicles. This seems no more than logical, given the relative simplicity of an electric motor by comparison with a diesel engine and the absence of clutches and gearboxes in the driveline. So are such claims substantiated by Shenzhen Bus Group’s experience to date? The short answer is no.
Ma explains that a typical total maintenance cost, over an eight-year life in service, for an 11-metre single-decker diesel-engined bus in the SBG eet had been around CNY480,000 (£53,000).
The whole-life maintenance cost, again over eight years, for a 10.5-metre, battery- electric single-decker is budgeted at CNY430,000 (£47,300) – hardly a saving to write home about.
But the overall operating cost picture
for electric buses changes dramatically when fuel costs are considered. A typical average fuel consumption gure for a
diesel single-decker in Shenzhen used to
be about 40 lit/100km (7.06mpg), reckons Ma. That made the fuel cost per diesel bus about CNY200 per 100km. Now the typical energy cost per vehicle for an electric bus
is about CNY70 per 100km. This means
the annual fuel bill for the eet of about CNY800 million (£88 million) has been cut to circa CNY480 million (£53 million).
Time is money: overnight charging at off-peak rates means huge savings in energy costs. The Shenzhen Bus Group fuel bill has been cut in half by switching from diesel engines to electric motors.
ELECTRIC BUSES IN CHINA
Residual values
One key question often raised by bus eet managers in the UK under pressure to switch wholesale from diesel to electric concerns the residual value of existing vehicles. Buses tend to have far longer in- service lives than trucks. What happens to old, or not so old diesel vehicles?
Even more pressing questions have been asked in London about the future of diesel/electric hybrid Routemasters from Wrightbus following the manufacturer’s collapse into administration a few months ago.
Last month’s news that Bamford Bus Company, owned by a member of the same Bamford family that runs the JCB construction equipment rm, may have alleviated some worries but it remains to be seen whether Bamford will be as co- operative as SBG’s suppliers have been.
“Our calculations on switching from diesel to electric were based on the residual value of our diesel buses,” says Ma. “Some still had about four years life left in them. The suppliers of our new electric buses, mainly BYD and Nanjing, bought the diesel buses
from us.”
COMMERCIAL VEHICLE ENGINEER > DECEMBER 2019 23